When done properly, blood pressure monitoring by people at home may be the best way to gauge daily levels, according to new guidelines issued by the American Heart Association (AHA).

While readings taken in a physician's office still have an important role to play in monitoring hypertension, "home blood pressure monitoring tends to reflect more closely the day-to-day blood pressure readings that people have," explains Dr. Daniel Jones, a co-author of the new guidelines and dean of the school of medicine at the University of Mississippi.

AHA experts last issued blood pressure management recommendations in 1993; the updated guidelines appear in a recent issue of the medical journal Hypertension.

Statistics Reflect Need for Vigilance

According to the AHA, nearly one in three US adults - about 65 million people - have high blood pressure. High blood pressure is defined as a consistent systolic pressure of 140 mm Hg (millimeters of mercury) or above and a diastolic pressure at or above 90 mm Hg.

Millions more may fall into the "prehypertension" category, with systolic readings between 120 mm Hg and 139 mm Hg and diastolic readings between 80 mm Hg and 89 mm Hg.

Since the 1980s, patient home monitoring of blood pressure using store-bought devices has become more accepted in the detection and management of high blood pressure.

As Dr. Jones explains, measurement of blood pressure at home may be more accurate than in the physician's office, since readings sometimes rise in the presence of healthcare providers.

"Almost everyone has what we call the 'white-coat effect' when they go into a physician's office - a response our brains have to being in a nervous situation," he says. "Home monitoring allows the measurement of blood pressure in an atmosphere that more closely measures daily activity."

Many studies in the last decade have confirmed that a combination of home and office monitoring is the best means of getting an accurate picture of hypertension risk, Dr. Jones notes.

"There's been lots of new data that has been meaningful about home blood pressure monitoring," he remarks. "That's reflected in these new guidelines."

Home Monitoring a Plus When Done Right

The new guidelines strongly support home monitoring, as long as it is done properly, Dr. Jones says. Appropriate arm cuff size remains a key component in any home blood pressure reading, he explains.

"There's a strong emphasis on proper cuff size in the recommendations, because of the growing problem of obesity in this country," Dr. Jones notes. "More and more, as our bodies get bigger, our arms get bigger, too, so larger and larger percentages of people need a larger-sized cuff for accurate measurement."

Dr. Jones says that decisions on the timing and method of home blood pressure monitoring is best left up to a patient and his or her physician.

However, in a statement, the AHA recommends that "ideally, blood pressure should be taken after several minutes' relaxation, when a person is comfortably seated in a chair, legs uncrossed, not talking, back and arm supported, and the cuff placed on bare skin."

Dr. Jones says the AHA does not endorse any particular brand of home monitor, but it does recommend that devices carry the seal of approval of the Association for the Advancement of Medical Instrumentation (AAMI). The US Food and Drug Administration (FDA) delegates testing and certification of home blood pressure monitors to the AAMI, Dr. Jones says.

He stresses that the new recommendations do not in any way diminish the importance of blood pressure readings taken in a physician's office.

"Office blood pressure measurement is a critical part of what's necessary for the good management of blood pressure problems," Dr. Jones says.

Always consult your physician for more information.